I've had the P0021 code for about 6 months but I haven't had it fixed because the car was running well enough. I believe I just need to order the front IVT sensor for about $150 but I've been putting it off.

During the last 2 weeks, while it has been very cold, the car sometimes has a rough idle. Yesterday, while accelerating, the SES light starting flashing and that appears to be a misfire based on some preliminary Google research.

Could the misfire & P0021 be related? I just had to replace a front hub and wheel bearing for $475 so I'm hoping this misfire is going to be an affordable repair. Please advise.

Nissan OBD-II Trouble Code P0021 download the engine control section in the service manual for more details. uwant to fix the problem or it will lead to other problems. sacan for codes and post all here. what maint. or work have u done to the car recently?how do u know its a misfire was it a code or u assumed it was misfiring? i wouldnt trust random sites since they might not have accurate info

I have the P0021 code for certain. I have reset the ECU several times and it always reappears.

The only thing I have done to try to fix the P0021 code was replace the front bank cam shaft position sensor. I'm not sure that was the correct sensor to replace or if I should have ordered the front IVT sensor, but that is the only work that has been done on the car regarding the P0021.

I am not certain that I have a misfire, but the "Service Engine Soon" light, which normally stays lit constantly because of the P0021 code, actually starting flashing while the car was idling and accelerating roughly. That was yesterday. Today, the car is running fine and still has the SES light, but it is not flashing.

Let me know if you need any more clarification. I'll also check to see if the car has any additional codes besides the P0021.

I clicked on your link and noticed that it could also be the crankshaft position sensor or the IVT solenoid.

What sucks is that I could pay about $300 to buy both sensors new or I could have the dealership perform a more thorough diagnostic with Consult to find out what is really wrong. They may charge $75 for the analysis, but then they don't charge you if you pay them to fix it.